The invention generally relates to a television system and more particularly to a system for and method of identifying a part (clip) of a video stream, the system and method being difficult to use for a commercial cutting function. The system and the method is applicable to a television system that permits the user to collect a variety of video clips such as program previews, commercials, representative scenes of a program and so on.
Recently, television (TV) broadcasting systems have increased channels in number. This often causes the user to find a difficulty in selecting programs to watch. In order to facilitate the selection of programs, broadcasting parties deliver program presentation scenes, program previews and so on between programs. Engineers of next generation broadcasting system are examining video environment in which the receiver automatically stores incoming program presentation scenes so as to enable the user to select programs meeting the user's taste without suffering from a flood of information. These environments will permit the user to search the stored program presentation scenes for favorite programs. In these environments, a television receiver can automatically record a highlight scene in each program, permitting the user to find a program he or she want by searching the recorded scenes. Also, if the user likes automobiles for example, he or she can control the television receiver to automatically accumulate commercials of automobiles to form a visual catalogue of automobiles.
The receiver automatically accumulating only particular programs or particular scenes is achieved by the broadcasting side attaching identifying codes to broadcast programs and scenes and by the receiver identifying desired programs and scenes through the identifying codes. Specifically, the broadcasting side attaches tags to parts of a transmitted video stream such as e.g., program presentation scenes, commercials and program previews (i.e., includes in the transmitted video stream a tag or data set for each video part spacing a predetermined fixed period or a period specified in the tag after the video part). This enables the receiver to identify the video part by using associated tags, permitting the receiver to accumulate desired ones of the tagged scenes.
On the other hand, EP 0 580 227 A discloses a "system for the transmission and reception of television signals upon payment" which is intended to enable publicity inserts to be not recorded in a secure manner. This function is very advantageous to the subscriber of fee-charging programs.
However, these tags also permit the receiver to easily remove or cut commercials and program presentation scenes inserted in the program in itself (commercial cutting). This is very disadvantageous for the sponsors to the program.
It is an object of the invention to provide techniques for collecting desired parts or scenes of a video stream by attaching a tag to each of the desired parts so as to prevent the tags from being used for commercial cutting (or information deletion, from the video stream, based on the tags associated with the commercial scenes).
According to the present invention, there is provided a method, for use in a broadcasting station of a television broadcasting system in which said broadcasting station transmits a video stream to receiving stations, of permitting each receiving station to extract a scene within the video stream, the method comprising the steps of:
The location information may be either an interval between the insertion of the tag and the transmission of the scene or a relative time with respect to a reference time. The location may be a fixed period.
According to a second aspect of the invention, there is provided a method, for use in receiving stations of a television broadcasting system wherein a broadcasting station transmits a video stream to said receiving stations, of identifying a scene within the video stream, the method comprising the steps of:
The receiving stations clip a predetermined length e.g. a largest one of a plurality of standardised lengths.
. The features and advantages of the present invention will be apparent from the following description of an exemplary embodiment of the invention and the accompanying drawings, in which
Throughout the drawing, the same elements when shown in more than one figure are designated by the same reference numerals.
FIG. 1 is a diagram showing a television (TV) broadcasting network or system which has incorporated a system for collecting desired video scenes or clips in accordance with the principles of the invention. In FIG. 1, the TV broadcasting network 8 comprises broadcasting facilities 2 for transmitting a broadcast stream including a video stream, a transmission media 3 through which the broadcast stream is delivered, and a multiplicity of TV receiver systems (or systems incorporating a TV tuner) 4.
The broadcasting facilities 2 comprises a TV transmitter 20 and a video-editing computer 24 that permits the operator to enter additional information (e.g., tags) to be included in a completed TV program (or a TV program which has been edited and compiled with commercials of the sponsors to the TV program and which is ready for transmission). The TV transmitter 20 includes a transmission controller 22 for controlling the TV transmitter 20.
On the other hand, the TV receiver systems 4 at least comprises a tuner 40 for selecting a specified one of the received channels; a transport processor 41 for IF (intermediate frequency) processing and demodulating the output signal from the tuner 40 into a video stream and an audio stream; a video stream processor 42 for extracting the additional information in the video stream from the transport processor 41 and for extracting or clipping a specified video scene (specified by a tag included in the additional information) from the video stream; I/O devices 46 for permitting the user to enter a command and data for the TV receiver system; a mass storage device 47 for storing collected video scenes (or clips); and controller for controlling the above-mentioned elements 40 through 42, 46 and 47. The mass storage device 47 may be a hard disc device or a rewritable optical disc device. If the TV receiver system 4 is a TV receiver, the system 4 further comprises a video processor 43 for providing a video output signal; an audio processor 44 for providing an audio output signal; and video and audio output devices. Bus lines 49 interconnect the elements 40 through 44, and 46 through 48.
It is noted that the transmission media 3 may be a terrestrial or satellite radio wave and/or cables. Also, the TV receiver system 4 may be any system having a TV tuner: e.g., a TV set, a video tape or cassette recorder, a rewritable optical disc, various kinds of set-top boxes, a computer with a tuner, other various information and/or communication system, etc.
FIG. 2 is a diagram showing an exemplary structure of a tag inserted in the video stream. FIG. 3 is a diagram illustrating the way of identifying a video scene by using a tag. In FIG. 2, a tag 1 at least comprises a scene ID (or title) 10 for the scene defined by the tag, a category 11 into which the scene defined by the tag is classified, a location 12 information used for finding the start time of the scene, and the length 13 of the scene.
The location 12 is preferably expressed by a time period that equals to the difference between the start time of the scene and the transmission time of the tag which precedes the scene start time. In other words, the tag has to be transmitted earlier than the scene start time by the period specified by the location 12 as shown in FIG. 3.
In FIG. 3, a tag with a scene ID of "PRG.REP" is transmitted D1 sec before a representative scene of a program segment "PRG.A1" whose period of time is L1 sec. Tags "CM1" and "CM2" are transmitted D2 and D3 sec before commercials CM1 and CM2 whose length are L2 and L3 sec, respectively. A tag with a scene ID of "PRG.A2" is transmitted D4 sec before a program segment "PRG.A2" whose length is L1 sec.
Alternatively, the interval between the scene start time and the tag transmission time (hereinafter referred to as "the offset interval") may be set to a fixed period of time, say, D sec. In this case, each tag has to be transmitted D sec before the scene associated with the tag; and the location 12 may be omitted.
It is noted that the value of the location field 12 of a tag may be expressed as the scene start time Ti measured from a reference time T set in the video stream as shown in FIG. 4 instead of using the interval between the scene start time and the tag transmission time (Di in FIG. 3).
A technique for attaching a tag to a desired video scene so as to prevent the tags from being used for commercial cutting will be described in the following.
FIG. 5 shows an exemplary tag created and an exemplary tag-attaching operation executed in a TV system 8 that uses tags without length information in accordance with the principles of the invention. In FIG. 5, the operator searches a completed TV program (or a TV program which has been edited and compiled with commercials of the sponsors to the TV program and which is ready for transmission) and finds a desired scene in step 100. The operator creates a tag 1a without length information 13 for the found scene in step 101. The operator makes a test in step 102 to see if the end of the program is reached. If not, the operator returns to step 100. If the end of the program has been reached in step 102, then the operator ends the operation.
It is noted that in response to a creation of a tag in step 101, the computer 24 automatically inserts the created tag in an appropriate position in the TV program in a timing as shown in FIG. 3 or 4 in step 103. The insertion of tags are achieved either by blanking interval multiplexing in case of analog TV system or by time-division multiplexing in case of digital TV system.
If the user desires to utilize the video scene or clip collection function, the user is asked which category of information he or she wants. For this the category list either in the pass storage device 47 or in an nonvolatile memory within the controller 48; and in response to a request from the user, the controller 48 may display the category list on the display device included in the video & audio output devices 45. Alternatively, a message "the category of this scene is 'CAR'" may be included in the corresponding scene. This enables the user to know a key word to use for the selection of category, permitting the user to collect information on the car thereafter. Once the user issues a clip collecting command specifying a desired category, the controller 48 keeps collecting and accumulating the video scenes with the tags whose category is CAR in the mass storage device 47 till the user issues another command to terminate the clip collection function.
In this embodiment, the TV receiver 4 clips a predetermined length of video scene from the position specified by the value Di or Ti in the location field 12 in step 105 and stores the clipped video scene in the mass storage device 47 in step 106 as shown in FIG. 6. Since the duration or time period of commercials has been standardized into some period, the predetermined length is preferably set to the largest one of the standard periods. Doing this enables each of the tagged video scenes of a specified category to be clipped in the maximum standardized length which is equal to or longer than the real length of the video scene.
It should be noted that the permission of tagging commercials is solely determined by the sponsor. In other words, a tag should not be attached to a commercial as long as the sponsor of the commercial does not permit the tagging to the commercial.
If this kind of tags were used for commercial cutting of a TV program, some of the tagged scenes might be clipped too much from the TV program. It is assumed that in order to cut the commercials, the user tries to remove all of the tagged scenes. Then, some of the commercials would remain unclipped at all because the tagging is not permitted to those commercials. Further, some portions of the program which are other than commercial might be clipped against the user's will if tags were attached to such the portions. These will result in a defective TV program so defective as to be unbearable to watch. Thus, removing the length information from tag provides us with a simplest but effective tagging technique that is unusable to commercial cutting.
Many widely different embodiments of the present invention may be constructed without departing from the scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.